The acquired immune deficiency syndrome (AIDS), whose etiologic agent is the human immunodeficiency virus, type 1 (HIV-1), has become an important public health issue. Virus infection generally is fatal; there is no vaccine available, and no demonstrated curative treatment exists. The main immunodominant structure of the virus is the envelope glycoprotein gpl6O, composed of the gpl2O + gp4l subunits. Because live attenuated or killed virus cannot be used as a vaccine, attention has focused on the use of synthetic peptides as vaccine candidates. The LTCB has an automated peptide synthesizer coupled to a computer-controlled robotic system ("PEPSCAN") that allows the rapid generation of multiple overlapping peptides of known length and sequence, which are deposited in the wells of a microtiter plate. Antigen-dependent T-cell clones can then be placed in these wells, stimulated with antigen, and the effects of the peptides on specific cell responses (cytokine production, etc.) can be assayed, either by immunoassay of the supernate for factor production or by bioassay in a cytokine-dependent system, and general cell proliferation and calcium flux can be determined. The goal of this project is to produce a large number of overlapping synthetic peptides based on the sequences of gpl2O, and examine the effect of these peptides, singly and in combination, on T-cells in vitro. This information will be important in HIV vaccine design.